1. FIELD OF THE INVENTION
The present invention relates to an air flow control device for a wall-mounted air conditioner with an upper outlet port and a lower outlet port. In particular, it relates to an air flow control device capable of optimizing temperature of the conditioned air blown out from the room side unit, which affects the sense of a user who is at a lower position than the mounting level of the wall-mounted room side unit.
2. DISCUSSION OF BACKGROUND
FIG. 13 is a vertical sectional view showing the room side unit in a conventional air conditioner as, for example, disclosed in Japanese Unexamined Patent Publication No. 191842/1984. In FIG. 13, reference numeral 1 designates an upper air-blowing fan (crossflow fan) which is disposed at an upper portion in the room side unit. Reference numeral 2 designates a lower air-blowing fan (crossflow fan) which is disposed at a lower portion in the room side unit. Reference numeral 3 designates a room side heat exchanger which is arranged between the upper air-blowing fan 1 and the lower air-blowing fan 2. Reference numeral 4 designates an upper outlet port which is formed in a upper front portion of the room side unit, and reference numeral 5 designates a lower outlet port which is formed in a lower front portion of the room side unit. Reference numeral 6 indicates the flow of the conditioned air which is blown out from both ports 4 and 5 by means of both fans 1 and 2 after the air in the room has been sucked through the room side heat exchanger 3.
FIG. 14 is a block diagram showing an air-blowing fan control system which is provided in the room side unit of the conventional air conditioner as shown in FIG. 13. Reference numeral 11 designates air-blowing fan operation mode determining means for determining the operation mode of both fans; 12, air-blowing fan operation control means for controlling the operations of both fans in accordance with the operation mode determined by the operation mode determining means 11; 14, heat exchanger temperature detecting means; 15, outlet port air temperature detecting means. Reference numeral 16 designates load calculating means for calculating a load based on the detected temperature signal from the heat exchanger temperature detecting means 14 or the detected temperature signal from the outlet port air temperature detecting means 15 so as to feed the results of the calculation to the operation mode determining means 11.
The operation of the air-blowing fan control system will be described in reference to FIG. 15 wherein the operation modes of the fans and the temperatures of the heat exchanger are shown in graphical representations.
When "heating" operation starts, both fans 1 and 2 maintain their OFF mode as shown in FIG. 15 at (a) and (b) until the temperature of the heat exchanger 3 reaches a preset value A, because the temperature of the heat exchanger 3 is lower than that value immediately after the "heating" operation has started. When the temperature of the heat exchanger 3 reaches the value A as shown in FIG. 15 at (c), the upper air-blowing fan 1 is driven in its low speed mode. When the temperature of the heat exchanger reaches a preset value B, the fan 1 is driven in its high speed mode. In addition, when the temperature of the heat exchanger 3 rises to a preset value C, the lower blowing fan 2 is driven in its low speed mode. When the temperature reaches a preset value D, the lower blowing fan 2 is driven in its high speed mode.
Now, the operation of the system will be explained in reference to FIG. 14. The detection temperature signal from the heat exchanger temperature detecting means 14 or the detection temperature signal from the outlet air temperature detecting means 15 is fed to the load calculating means 16 to calculate the load condition. The load signal representing the calculated load condition is fed to the fan operation mode determining means 11 to determine the operation modes of both fans depending on the load signal. The determined operation modes are instructed to the control means 12 for controlling the operations of both fans. As a result, the control means 12 controls both fans 1 and 2 in accordance with the instructed operation modes.
In the conventional air conditioner, when both fans are driven at substantially the same revolution, the upper and lower outlet ports 4 and 5 blow out at substantially equal wind volume the air that has passed through the heat exchanger 3.
When the wall-mounted room side unit carries out the "heating" operation and a sufficient volume of the heated air is blown out of the respective outlet ports 4 and 5, the heated air from the upper outlet port 4 holds down the heated air from the lower outlet port 5 to prevent the heated air from the lower outlet 5 from rising. It allows the heated air to circulate around the user's feet and legs and to provide comfortable air-conditioned atmosphere without uneven distribution in the temperature.
The conventional air conditioner carries out the operation control of both fans, depending on the load conditions being calculated based on the heat exchanger temperature or the outlet air temperature as shown in FIG. 15. As a result, when the air conditioner is wall-mounted so as to have both outlets at positions higher than the user, it does not always provide comfortable air circulation to the user, an it also has a disadvantage in terms of energy-saving because it wastefully heats the upper space in the room.
When the wind rates at both fans are set to a "strong wind" mode and sufficient volumes of the conditioned air are provided from the fans, it is possible to obtain air-conditioning without uneven distribution in the temperature. When the wind rates are set to a "weak wind" mode and the conditioned air passing through the heat exchanger is distributed to both outlet ports, the conditioned air blowing out of the lower outlet port is difficult to reach the user's feet and legs. In particular, at the "heating" operation, the heated air from the upper outlet port can not hold down the heated air from the lower outlet port. As a result, the heated air from the lower outlet port can not circulate in a good manner to cause uneven distribution in the temperature, thereby having a disadvantage that the user's feet and legs are not heated.
In addition, when the user who comes into the conditioned room from outside wishes a "spot-heating" or a "spot-cooling" operation wherein the user wants to heat or cool his or her body exclusively the conventional air conditioner has a further disadvantage in that it is difficult to use effectively the conditioned air from one of the outlet ports.
It is an object of the present invention to eliminate the disadvantages in the conventional air conditioner as explained above.
It is another object of the present invention to provide an air flow control device for an air conditioner capable of carrying out optimum controls of the conditioned air blown out of the outlet ports so that the user who is at a lower level than the mounting level of the wall-mounted air conditioned can feels good comfort, and provide optimum comfortable atmosphere, depending on the user's desires.
The foregoing and the objects of the present invention have been attained by providing an air flow control device for an air conditioner comprising input producing means for outputting a condition required for the outlet air and phenomenon information on the outlet air, control means for controlling at least upper and lower air-blowing fans based on the condition and phenomenon information outputs from the input producing means so as to optimize the outlet air to the user who is at a lower level than the outlet level.
In accordance with the present invention, when the outlet air conditions (namely, selection among the "strong wind" mode, the "weak wind" mode and the spot mode) and the phenomenon information on the outlet air (namely, temperature information on the air from the lower outlet port) are sent from the input producing means into the control means, the control means controls mainly both fans so that the atmosphere where the user is experiences comfortable air conditioning.
As a result, the present invention can carry out optimum controls of the outlet air and also provide comfortable atmosphere as the user wishes.